lmkd: Enable new kill strategy, add and adjust required system properties
Enable new kill strategy when PSI mode is used in combination with
ro.lmk.use_minfree_levels=false. Adjust ro.lmk.swap_free_low_percentage,
introduce ro.lmk.psi_partial_stall_ms and ro.lmk.psi_complete_stall_ms
system properties to support two levels of PSI events measuring partial
and complete stalls. Add ro.lmk.use_new_strategy system property to switch
to the old strategy if necessary.
Bug: 132642304
Test: lmkd_unit_test, ACT memory pressure tests
Change-Id: I6f1b65e19dbe9b58c862e5e4255270c82f0afb9a
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
diff --git a/lmkd/README.md b/lmkd/README.md
index a735955..8a73692 100644
--- a/lmkd/README.md
+++ b/lmkd/README.md
@@ -80,3 +80,11 @@
the threshold when system does not recover even
after a kill. Default for low-RAM devices = 50,
for high-end devices = 10
+
+ ro.lmk.psi_partial_stall_ms: partial PSI stall threshold in milliseconds for
+ triggering low memory notification. Default for
+ low-RAM devices = 200, for high-end devices = 70
+
+ ro.lmk.psi_complete_stall_ms: complete PSI stall threshold in milliseconds for
+ triggering critical memory notification. Default =
+ 700
diff --git a/lmkd/lmkd.c b/lmkd/lmkd.c
index 42e3db3..1db3d5a 100644
--- a/lmkd/lmkd.c
+++ b/lmkd/lmkd.c
@@ -133,6 +133,11 @@
/* ro.lmk.thrashing_limit_decay property defaults */
#define DEF_THRASHING_DECAY_LOWRAM 50
#define DEF_THRASHING_DECAY 10
+/* ro.lmk.psi_partial_stall_ms property defaults */
+#define DEF_PARTIAL_STALL_LOWRAM 200
+#define DEF_PARTIAL_STALL 70
+/* ro.lmk.psi_complete_stall_ms property defaults */
+#define DEF_COMPLETE_STALL 700
/* default to old in-kernel interface if no memory pressure events */
static bool use_inkernel_interface = true;
@@ -174,6 +179,8 @@
static bool use_minfree_levels;
static bool per_app_memcg;
static int swap_free_low_percentage;
+static int psi_partial_stall_ms;
+static int psi_complete_stall_ms;
static int thrashing_limit_pct;
static int thrashing_limit_decay_pct;
static bool use_psi_monitors = false;
@@ -2406,8 +2413,15 @@
}
}
-static bool init_mp_psi(enum vmpressure_level level) {
- int fd = init_psi_monitor(psi_thresholds[level].stall_type,
+static bool init_mp_psi(enum vmpressure_level level, bool use_new_strategy) {
+ int fd;
+
+ /* Do not register a handler if threshold_ms is not set */
+ if (!psi_thresholds[level].threshold_ms) {
+ return true;
+ }
+
+ fd = init_psi_monitor(psi_thresholds[level].stall_type,
psi_thresholds[level].threshold_ms * US_PER_MS,
PSI_WINDOW_SIZE_MS * US_PER_MS);
@@ -2415,7 +2429,7 @@
return false;
}
- vmpressure_hinfo[level].handler = mp_event_common;
+ vmpressure_hinfo[level].handler = use_new_strategy ? mp_event_psi : mp_event_common;
vmpressure_hinfo[level].data = level;
if (register_psi_monitor(epollfd, fd, &vmpressure_hinfo[level]) < 0) {
destroy_psi_monitor(fd);
@@ -2439,14 +2453,29 @@
}
static bool init_psi_monitors() {
- if (!init_mp_psi(VMPRESS_LEVEL_LOW)) {
+ /*
+ * When PSI is used on low-ram devices or on high-end devices without memfree levels
+ * use new kill strategy based on zone watermarks, free swap and thrashing stats
+ */
+ bool use_new_strategy =
+ property_get_bool("ro.lmk.use_new_strategy", low_ram_device || !use_minfree_levels);
+
+ /* In default PSI mode override stall amounts using system properties */
+ if (use_new_strategy) {
+ /* Do not use low pressure level */
+ psi_thresholds[VMPRESS_LEVEL_LOW].threshold_ms = 0;
+ psi_thresholds[VMPRESS_LEVEL_MEDIUM].threshold_ms = psi_partial_stall_ms;
+ psi_thresholds[VMPRESS_LEVEL_CRITICAL].threshold_ms = psi_complete_stall_ms;
+ }
+
+ if (!init_mp_psi(VMPRESS_LEVEL_LOW, use_new_strategy)) {
return false;
}
- if (!init_mp_psi(VMPRESS_LEVEL_MEDIUM)) {
+ if (!init_mp_psi(VMPRESS_LEVEL_MEDIUM, use_new_strategy)) {
destroy_mp_psi(VMPRESS_LEVEL_LOW);
return false;
}
- if (!init_mp_psi(VMPRESS_LEVEL_CRITICAL)) {
+ if (!init_mp_psi(VMPRESS_LEVEL_CRITICAL, use_new_strategy)) {
destroy_mp_psi(VMPRESS_LEVEL_MEDIUM);
destroy_mp_psi(VMPRESS_LEVEL_LOW);
return false;
@@ -2831,6 +2860,10 @@
property_get_bool("ro.config.per_app_memcg", low_ram_device);
swap_free_low_percentage = clamp(0, 100, property_get_int32("ro.lmk.swap_free_low_percentage",
low_ram_device ? DEF_LOW_SWAP_LOWRAM : DEF_LOW_SWAP));
+ psi_partial_stall_ms = property_get_int32("ro.lmk.psi_partial_stall_ms",
+ low_ram_device ? DEF_PARTIAL_STALL_LOWRAM : DEF_PARTIAL_STALL);
+ psi_complete_stall_ms = property_get_int32("ro.lmk.psi_complete_stall_ms",
+ DEF_COMPLETE_STALL);
thrashing_limit_pct = max(0, property_get_int32("ro.lmk.thrashing_limit",
low_ram_device ? DEF_THRASHING_LOWRAM : DEF_THRASHING));
thrashing_limit_decay_pct = clamp(0, 100, property_get_int32("ro.lmk.thrashing_limit_decay",